Means for cooling internal combustion engines



March 18, 1958 A. WQMA L. ETAL. ,8

MEANS FOR COOLING INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1955 4 Sheets-Sheet 1 I ck flz a orizqg March 18, 1958 A. w. MALL ETAL 2,827,026

MEANS FOR COOLING INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1955 4 Sheets-Sheet 2 4 4? gm @MM (/fi przzizg March 18, 1958 A. w. MALL E'E'AL 2,827,026

MEANS FOR COOLING INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1955 4 Sheets-Sheet 3 March 18, 1958 A. w. MALL ETAL 2,827,026

MEANS FOR COOLING INTERNAL COMBUSTION ENGINES Filed Sept. 19, 1955 4 Sheets-Shae 4 nite States Arthur W. Mall, Flossmoor, and Charles A. Mattson,

Chicago, 111., assignors to Mail Tool Company, Chicago, 111., a corporafion of Illinois Application September 19, 1955, Serial No. 535,006

2 Claims. (Cl. 123-4L05) This invention relates to a thermostat controlled air cooling system for an internal combustion engine, and more particularly, means for controlling the flow of air through such a system.

It is a principal object of this invention to provide a forced air system for cooling the cylinder of a portable internal combustion engine mounted within a weather protective shroud.

it is another object of this invention to provide temperature responsive means for regulating the flow of cooling air through the system.

It is a further object to provide a forced air system which may be closed to atmosphere to facilitate starting a cold engine under arctic conditions, and opened to atmosphere for operating the engine'under normal conditions, and temperature responsive means for automatically making these adjustments.

Further objects will appear from the following, read in connection with the accompanying drawings, wherein:

Fig. 1 is a view in perspective of the weather protective shroud containing an internal combustion engine and the temperature responsive control for the cooling system therefor;

Fig. 2 is a detail view in section taken along lines 2-2 of Fig. 1;

Fig. 3 is a section taken along lines 3-3 of Fig. 2;

Fig. 4 is a section taken along lines 4-4 of Fig. 3;

Fig. 5 is a view illustrating the temperature responsive element in position in the air cooling system;

Fig. 6 is a section taken along lines 6-6 of Fig. 4;

Fig. 7 is a section taken along lines 77 of Fig. 4;

Fig. 8 is a section taken along lines 83 of Fig. 3; and

Fig. 9 is an exploded View showing certain of the structural parts of the air cooling system disassembled.

A protective shroud l encloses engine 11 (Figs. 2, 3) which has the usual functional parts, including a crankshaft 12 and cylinder casting 13, mounted on a skid 14 and provided with handlebars 15 to facilitate carrying or sliding the unit from one location to another. The shroud 10 is designed to accommodate an electric generator (not shown) driven from the internal combustion engine 11, which serves as a prime mover for the generator. 111 such an installation, the gear 15 is engaged by a driven gear (not shown) connected to the rotor shaft of the generator.

In the form shown, the internal combustion engine is a single cylinder two-cycle engine obtaining fuel from a tank carried within the shroud 10, above and behind the engine 11, access to which is provided by removing a fuel tank cap 16. The engine 11 exhausts through a muflier assembly 17 which projects through the side panel 18 of the shroud 10. This same side panel 18 is provided with vents to promote circulation of air within the shroud 10.

Supported on the front panel 19 of the shroud is a casting 20 (Fig. 2) held in place by means of bolts 21.

Casting is formed with a curved Wall 22 comprising one part of an involute fan housing and is mounted over an opening 23, in the front panel 19 of the shroud 10. Thin walls 24 in the casting 20 extending forwardly of the shroud, enclose a chamber 25 communicating to the interior of the fan housing through an axially disposed opening 26 in the interior wall 27 of the casting 20. To control the admission of air to the fan housing an assembly 28 of adjustable louvers 29 is bolted over the front end of the chamber 25.

The open portion of the casting 20 facing the interior of the shroud and formed as an involute comprises with a companion casting 30 the housing for the fan 31 carried on the end of crankshaft 12 and provides a blower forcing cooling air past the engine. A flared stamped part 32 is fastened in place around the opening 26, di-

recting air into the blades of the fan.

An opening 33 is provided to permit air under pressure to exit from the pressure end of the involute (Figs. 3, 9) toward the engine cylinder 13 mounted behind the casting 30, through a passage 35 formed by walls 35, 37 and 38 on the rear of the casting.

Air is forced past cylinder 13 for cooling purposes, and into a duct 39 mounted to communicate with the passage 35. Duct 39 may be formed as a stamped part or as a casting adapted to be bolted on the rear edges of the walls defining passage 35. In order to direct the cooling air toward the outside of the shroud, duct 39 is formed of right angularly disposed interior walls 40, 41 which defiect air forced past the cylinder 13 toward opening 42 in the side of the duct.

The side panel 18 of shroud 10 is provided with a vent 43 having permanently fastened louvers 44 for shielding the interior of the shroud from the entry of ice, snow and other undesired matter. To permit the cooling air to exhaust to atmosphere through the panel 13 the open side 42 of duct 39 is directed toward vent 43.

Within duct 39, as shown best in Fig. 4, is an interior wall 45 curved to deflect a portion of the cooling air back toward the front of shroud 10. The Wall 45 forms a scoop directing a portion of the cooling air through a tubular conduit or passage 46 formed in casting 3t). Mounted within the tubular conduit or passage 46 is a temperature responsive mechanism 47 connected by means of a linkage 48 supported within a connecting passage 49 extending toward the front of the housing and forwardly of the fan housing cavity, to the louvers 29 for adjusting the angle of the louvers to either admit or exclude cooling air.

In the preferred form of the invention shown, the temperature responsive element 47 is a bellows actuated plunger connected to a shaft (Fig. 5) which operates a bell crank 61 pivotally supported on a pin 62 mounted on casting 2G. The forwardly extending arm 63 of the bell crank is fastened by a pin 64 to a lug 65 slidably mounted on shaft 66 of the louver adjusting mechanism. The louvers 29 are pivotally supported on brackets 67 on each end of the louvers which, in turn, are hung on pins 63 fastened on the flanges 69, 70 carried on the rear face of the plate 25. The brackets 67 on the end of the louvers adjacent shaft 66 are provided with a rearwardly extending arm 71 which is fastened to strap 72. The lower end of shaft 66 is bent at right angles and extends through an opening 73 in the strap 72. By raisv ing shaft 66 from the position illustrated in Fig. 9, the louvers 2% may be swung inwardly and opened to allow the entrance of air to the engine cooling system. The louvers 29 are normally urged toward the closed posi- 0 tion by means of a spring 74 (Fig. 5) fastened to the lower end 75 of strap 72 and to the upper end 76 of flange 69.

Bell crank lever-arm 63 fastenedto log 65 raisesand lowers the lug in accordance with the position of the temperature responsive element 47. Surrounding shaft 66 is a compression spring 78- seating at its upper end 79--against the bottom edge of the lug and at its lower end 80 against a collar 81 fastened on the shaft.

nuts 82 against which the upper edge of lug 65 sits when the-lug is raised. Spring 78'urges the lug 65'to'wardjthe upper" position on the shaft and motion is transmitted the bell crank lever-61 providesinsuflicient force to free the luvers,'a sudden blow may be trans-mittedto the upperend of shaft 66 by means ofa plunger 85 s'lidably mounted within a screw threaded insert 86 supported in an opening 87-providedabove the upper endof shaft-66 inthe wall 88 of the casting 20; A spring 89 under the cap 99 holds-the plunger 85in raised position but the top of the cap 90 may be struck to drive the plunger 85 down toward the shaft 66 to free the louvers.

Under normal temperature and humidity conditions, the temperature responsive element 47 positions'the louvers. 29'so'as to admit air into the system to cool the engine'cylinder. Even during starting, unless the temperature of the atmosphere" in which the unit is being operated is very low, the louvers will open to allowthe free circulation of air by means of the blower carried on the end of the engine'crankshaft. temperature of the atmosphere is extremely low, as is encountered in the Arctic, the'temperature responsive element positionsthe louvers closed.

If the louvers are stuck or frozen in a partially opened condition, the louver adjustment mechanism may be freed by striking the plunger projecting above the top of the housing, a sharp blow with a hammer or other instrument, which jars the loose parts of the mechanism allowing it to close and seal the opening into the shroud surrounding the engine. a

After the engine is started, and the temperature'rises in the cylinder, the temperature responsive element gradually moves. to partially open the louvers to admit air from the atmosphere to circulate through the shroud and plish this result. 7

Under normaloperating conditions, with the louvers partially or fully opened, a major factor of the air forced past the cylinder exhausts through the air duct out the vent: provided in the side pa'nelofthe shroud. A small portion of the air forced past. the cylinder, is returned by The upper'end' of the shaft 6 6is screw threaded and receives In' the eventthe louvers 29-become stuck or frozen and lowering lug 65 by rotating However, when the 4 the front of the shroud where'it is deflected toward the axially disposed opening in the fan housing.

in Figs. 1 and 4, the path taken by the cooling air in the system is indicated by arrows and it may readily be observed that a portion of the air forced past the cylinder by the fan is returned pastthe temperature responsive element to the chamber in back of the louvers where it may be recirculated by the fan; after passing through the axially disposed openingin the fan housing.

The invention has been described with reference to particnlar preferred embodiments, audit is understood the details are merely illustrative andthat the' invention may be carried out in other ways without, departing, from: the true spirit and scope of the appendcdclaims.

We claim:

1. A cooling system for an internal combustion engine comprising a blower for raising the pressure of air obthe scoop positioned in the air duct and flows through a 0 passagecontainingthe, temperature responsive element to tained from an inlet chamber, said inlet chamber having an intake opening for admitting fresh air'at atmospheric pressure into the system, a passage connectingwith the blower directing air-past the engine to-a discharge pointof reduced pressure, a second passage connecting-the discharge point with the inlet chamber for recirculating a portion of the air moved past the engine, a temperature responsive element positioned in said second p'assage and actuated by the recirculated air, andcontrol' means operated by said temperature responsive element to close .the intake opening and adjustthe rate'of admission-of fresh air to the inletchamber whereby-apartof 'theair passing 'the engine is; recirculated through the second passage to the blower in varying quantities depending upon the degree the intake opening'is' closed. Y

, 2. A cooling system for an internal combustion engine comprising a blower for raising the-pressure of air ohtained from an inlet chamber, said inlet chamber having an intake opening for; admitting fresh air at atmospheric pressure to the system, adjustable louvers across said opening, a housing for said blower. formed with an-intake opening communicating with said chamber and'an outlet opening arranged adjacent the engine throughwhich-air responsive elementpositioned in said second passage-and l actuated by the recirculated air, and a linkage connecting said temperature responsiveelement and the adjustablelouvers to, close thetintake opening and adjust the rateof admission of fresh air to the inlet chamber whereby a" part of the air passing the engineis diverted "by said, scoop and recirculated through'thesecond passage to the blower in varying quantities depending upon the degree the intakeopening is closed. a 7

References fiited in the file of this patent UNITED STATES PATENTS 1,573,641 Hunt ,F eb. 1r6, 192161 

